Sixty-eight percent of asset owners globally believe the integration of ESG strategies has significantly improved returns, said a survey by State Street Global Advisors released Wednesday.

SSGA surveyed 475 asset owners, including pension funds, endowments and foundations, between December and January. Of the 475 respondents, 80% reported having some form of environmental, social and governance strategy in their portfolios.

Although the results indicate high adoption of ESG strategies and satisfaction with their performance, the survey also found the depth of ESG exposure in asset owners' portfolios is low.

Only 17% of survey respondents reported that more than 50% of their total assets have exposure to ESG factors; 39% said between 25% and 49% of their assets have exposure; and 44% said between 1% and 25%.

When it comes to further ESG incorporation, asset owners reported several barriers.

Forty-nine percent of asset owners said fees and expenses are the main barriers to further ESG incorporation, followed by a lack of internal knowledge on ESG investing.

Another 57% of respondents said it's difficult to benchmark performance against peers, and 56% said accurate assessment of external ESG managers is difficult.

Other findings from the survey include 69% of respondents said that integrating ESG strategies into their portfolios has helped with managing volatility, and 78% of assets owners have some level of ESG engagement with portfolio companies.

“There's a collective shift in the institutional investment world right now that has asset owners and managers thinking differently about the full implications of their investments," said Chris McKnett, managing director and head of global ESG at SSGA, in a news release on the results. "For the majority, the question is no longer, 'should we consider ESG as part of our mandate,' the question is 'how are we actively pursuing opportunities with our investments that help us reach our financial goals, while encouraging change in the process?'"